Microchip Technology 11LC161T-I/MS

Overview

11LC161T-I/MS from Microchip Technology Inc. is a 16 Kbit (2,048 × 8) serial EEPROM with UNI/O® single I/O bus interface, operating from 2.5V to 5.5V across -40°C to +85°C industrial temperature range. It features 16-byte page-write buffer, STATUS register with WIP/WEL bits, and hardware block write protection for 0%, 25%, 50%, or 100% of memory array. Used in embedded system configuration storage where minimal pin count and low standby current (<1 µA) are critical.

For engineers reviewing the 11LC161T-I/MS datasheet, 11LC161T-I/MS pinout, 11LC161T-I/MS application, or 11LC161T-I/MS equivalent, key selection considerations include its 8-lead MSOP package, UNI/O® protocol timing tolerance (±0.5% frequency drift per byte), Schmitt-trigger SCIO input, slope-controlled output to suppress ground bounce, and verified 1,000,000 erase/write cycles with >200-year data retention.

Technical Context

The 11LC161T-I/MS implements Manchester-encoded UNI/O® communication over a single bidirectional SCIO line, extracting clock and data from one signal stream. Its internal architecture includes a page latch buffer, HV generator for EEPROM programming, and re-synchronization circuitry that adjusts to master clock drift and edge jitter during each MAK bit.

It supports full read/write operations via command set including READ (0x03), WRITE (0x6C), RDSR (0x05), WRSR (0x6E), and ERAL (0x6D), with write enable latch control (WREN/WRDI) and status monitoring. Block protection is configured nonvolatilely via BP0/BP1 bits in the STATUS register, independent of VCC state.

Key Specifications

Pinout & Package

11LC161T-I/MS is packaged in an 8-lead MSOP (MS) package with exposed pad (non-electrical), pin-compatible with SOIC and PDIP footprints but with reduced footprint area. Pin 1 is SCIO, pin 2 is VSS, pin 3 is NC, pin 4 is NC, pin 5 is NC, pin 6 is NC, pin 7 is NC, and pin 8 is VCC - consistent with MSOP pinout defined in DS22067J-page 2.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial EEPROM applications.

Compared with 11AA161T-I/MS, the 11LC161T-I/MS trades 1.8V support for improved noise immunity above 2.5V; compared with AT24C128-MSH-T, it reduces interface complexity and pin count at the cost of density and protocol familiarity.

Availability

11LC161T-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration storage, medical device configuration memory, and automotive body control module applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for 11LC161T-I/MS includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and memory products, with emphasis on embedded control and reliability.

The 11LC161T-I/MS belongs to Microchip's 11XX UNI/O® serial EEPROM family, designed specifically for ultra-low-pin-count, low-power nonvolatile storage in resource-constrained embedded systems.

FAQ

What is the UNI/O® interface used by the 11LC161T-I/MS, and how does it differ from I²C or SPI?

The 11LC161T-I/MS uses Microchip's patented UNI/O® interface - a single-wire, Manchester-encoded serial bus that combines clock and data into one SCIO signal. Unlike I²C (2-wire) or SPI (3–4 wires), UNI/O® eliminates dedicated clock lines and bus arbitration, reducing MCU pin count and PCB routing complexity. It achieves 100 kbps effective throughput with built-in clock recovery and jitter tolerance, making it ideal for space- and pin-constrained designs where 11LC161T-I/MS replaces larger interface EEPROMs.

Does the 11LC161T-I/MS support hardware write protection, and how is it configured?

Yes, the 11LC161T-I/MS supports hardware block write protection via two nonvolatile BP0 and BP1 bits in its STATUS register. These bits can be programmed using the WRSR (0x6E) command to protect 0%, 25%, 50%, or 100% of the 16 Kbit memory array. Protection remains active across power cycles and is independent of the write enable latch (WEL), providing robust safeguarding against accidental or malicious writes - a key reliability feature of the 11LC161T-I/MS.

What is the maximum write speed and page size of the 11LC161T-I/MS?

The 11LC161T-I/MS has a fixed page size of 16 bytes and supports page-write operations up to 100 kHz bus frequency. Its self-timed write cycle completes in ≤10 ms for full-page writes (TWC), with no external timing constraints. The 16-byte buffer allows sequential data loading followed by a single NoMAK to initiate the internal erase-and-program sequence - optimizing write efficiency while maintaining compatibility with the 11LC161T-I/MS's UNI/O® protocol timing requirements.

Can the 11LC161T-I/MS operate down to 1.8V, and what is its valid supply voltage range?

No, the 11LC161T-I/MS is rated for 2.5V to 5.5V operation only. It does not support 1.8V - that functionality is reserved for the 11AA161T-I/MS variant in the same family. Operating the 11LC161T-I/MS below 2.5V may result in unreliable read/write behavior or failure to meet AC timing specifications. Always verify VCC compliance within this range to ensure correct 11LC161T-I/MS functionality in your design.

How does the STATUS register in the 11LC161T-I/MS assist in reliable write operations?

The STATUS register in the 11LC161T-I/MS provides real-time visibility into device state via two critical bits: WIP (Write-In-Progress) and WEL (Write Enable Latch). Software can poll WIP using RDSR (0x05) to determine when a write cycle completes - avoiding fixed delays - and verify WEL before issuing WRITE commands. This enables deterministic, failure-resilient firmware logic, directly enhancing system reliability during 11LC161T-I/MS configuration updates.